1. Field of the Invention
The present invention relates to computer network communications and in particular to methods and structures for simple yet robust and reliable file exchange between otherwise secured systems using a variety of communication media.
2. Discussion of Related Art
Computer networks are used for interconnection of a plurality of computer systems for purposes of exchanging information between such systems. In general, a network includes a number of computer systems interconnected by a one or more communication links. Local area network (LAN) is a term generally applied to relatively smaller networks wherein a number of computer systems are interconnected via a relatively short distance high-speed communication links. For example, a LAN may interconnect a number of computers within an office, a building or a campus. By contrast, wide area networks (WANs) tend to be larger networks comprising a larger number of computers interconnected by a wide variety of high-speed (shorter distance) and lower speed (longer distance) communication links. For example, a global business enterprise may interconnect their installations around the world with a WAN while each particular installation may utilize a LAN to interconnect its particular computer systems.
In a local area network it is common that all computers cooperate using the related low-level protocols. For example, all computers on a particular local area network (LAN) would typically share use of a single protocol such as TCP/IP, NETBEUI (from Microsoft), or IPX/SPX (from Novell). It is also common for multiple such protocols to be simultaneously operable over a particular LAN or WAN. Higher level networking protocols and applications then exchange data via these lower-level communication protocols.
Often a group of computer systems on a network are referred to as an enterprise. In general, as used herein, an enterprise is a large and diverse network connecting most major points in a company or other organization. As used herein, an enterprise may be synonymously referred to as a computing enterprise or a business enterprise.
It is common in computer networking to view the interconnected communications as a layered model, specifically a seven layer model often referred to as the Open Systems Interconnect (the so called OSI standard maintained by the International Standards Organization (ISO)). Higher layers in the model transfer their information to a corresponding next lower layer for detailed management of lower-level transmission issues. The higher layers of the model therefore communicate in effect with corresponding higher level components in other computers on the network. Each lower level of the OSI model, in turn, communicates with its corresponding lower layer embodied within other computers on the network. Such a layered model allows computer networking software to be developed in accordance with standard programming interfaces between the various layers. A particular layer may therefore be replaced by an equivalent component which provides similar services to the layer above and invokes lower-level services from a lower layer in accordance with a standard interface definition.
In general, wide area networks (WANs) use a wider variety of physical communication media for the exchange of data among a more geographically disperse set of computing systems. Each such diverse lower-level physical communication medium utilizes a corresponding lower level protocol layer in, for example, the OSI model.
Security is a constant challenge for networks and computing engineers responsible for networks. In particular, in wide area network applications, it is important for computing systems attached to such a network to secure their resources from inappropriate, unauthorized access. The Internet is an example of a global wide area network where security measures are often critical to an ongoing business enterprise connected to the Internet. Such security measures are required to assure that unauthorized third parties, anywhere in the world, cannot gain access to sensitive materials within the enterprise via the global, publicly accessible, Internet.
Though such security measures (often referred to as firewalls) are vital to secure each particular enterprise, they're very existence creates the burden for those trying to legitimately exchange information between enterprises via such global, public networks. A user in one particular computing enterprise encounters a number of difficulties exchanging data with another user in a different computing enterprise via computer system to computer system network communication links. Though the communication capability may exist, for example via the Internet, safeguards and security measures (firewalls) within each enterprise makes such enterprise to enterprise exchanges difficult--exactly as they are intended to do.
In general such firewall security measures operate at lower layers of the network communication layered model to filter out potentially harmful network data exchange. For example, the firewall may permit certain protocols to be exchanged only among certain network devices known to be physically secured within the enterprise. Network devices not within the permitted scope of secured devices are not permitted to use the filtered protocols. Should such un-authorized devices attempt such communications, the firewall simply discards their network data transfer requests.
A significant number of standard networking applications are capable of exchanging certain types of information without interference from security and safeguard mechanisms within an enterprise. Such applications are generally considered secure in that they cannot, in general, cause harm to or disrupt operation of the receiving computer system. For example, electronic mail messages are generally considered benign and therefore readily exchanged between most systems on the Internet regardless of implemented security measures and safeguards within each enterprise. Other standard protocols including hypertext transfer protocol (HTTP) are similarly limited in their capability and may therefore allow further exchange of information between computing systems which are otherwise secured. Still other "transport" techniques may be utilized to exchange information among otherwise secured business enterprises. For example, manual procedures such as transferring information via magnetic or optical medium, or other direct communication links such as modems which bypass secured network connections may be used to exchange information among the otherwise secured computing enterprises.
It is generally known to use such widely available networking protocols for purposes of exchanging information between otherwise secured computing enterprises. For example, attachment files are often transmitted with email messages to permit additional information to be transmitted with the known message. Such attachment files may, in general, contain any further information (textual or raw binary data) relating to the underlying email message.
However, use of such higher level protocols (email exchange protocols) or manual transmission techniques (i.e., exchange via a magnetic or optical medium) does not provide the robust reliable exchange of information normally required for exchange of large quantities of information between two otherwise secured computing enterprises. For example, and when using the email messages to exchange large volumes of information via attached files, there are no automated procedures known for assuring that the entire set of attached files are received once, only once, and reassembled in the correct order.
In view of the above discussion, it is evident that a need exists for improved protocol management to permit the exchange of data between processes on otherwise secured systems. Such systems may be geographically dispersed and interconnected via a wide area networking or generally devoid of network communication interconnection. Such protocol management would ideally assure robust, reliable transport of information between such otherwise secured computing enterprises.